The FAA has issued a policy document for public comment on Chemical Oxygen Generators.The policy is driven in response to a recent Airworthiness Directive imposed on Chemical Oxygen Generators installed in lavatories.
Airworthiness Directive (AD) 2011-04-09, Various Transport Category Airplanes Equipped With Chemical Oxygen Generators Installed in a Lavatory, required operators to disable lavatory oxygen systems with chemical oxygen generators.
14 C.F.R. 121.1500(b)(1)(ii) required all oxygen masks to be removed from air carrier lavatories.
14 C.F.R. 121.1500(b)(1)(iii) required air carriers to ensure that their crew emergency procedures included a visual check of the lavatory as a priority following any event when oxygen masks were deployed in the cabin.
FAA guidance issued this summer requires ASIs to ensure verify that their assigned carriers have revised the appropriate manuals and training programs to comply with § 121.1500.
The problem with this AD and guidance is that it requires air carriers to take steps that put them out of compliance with the oxygen mask requirements of 14 C.F.R. §§ 25.1443 and 25.1447.
The draft guidance that has been released for comment is entitled Chemical Oxygen Generator Installations PS-ANM25-04, and it provides a mechanism that would permit air carriers to meet the oxygen mask requirements of 14 C.F.R. §§ 25.1443 and 25.1447 as well as the Airworthiness Directive through an Alternative Method of Compliance (AMOC) associated with the Lavatory Oxygen Generator rule.
The draft policy explains the methodology recommended for AMOCs to this Airworthiness Directive:
The ARC recommended that COGs have the following additional certification criteria:
Each COG or its installation must be designed to be secure by meeting one of the following conditions:
(1) Resistance to tampering, or
(2) A combination of resistance to tampering and active tamper-evident features, or
(3) Installation in a location or manner whereby any attempt to access the COG would be immediately obvious, or
(4) A combination of approaches captured in paragraphs (1), (2), or (3) of above that the Administrator finds acceptable to provide a secure installation.
The draft guidance explains that installations approved under this AMOC policy would be exempted from a later Airworthiness Directive that is expected to be issued with terminating actions. The policy reason for this is “because the broad range of expertise represented on the ARC makes it unlikely that any comments received as a result of the public notice and comment process would substantively affect the retrofit designs approved on the basis of the ARC recommendations.”
Operators that follow the guidance in this policy statement and have COG installations approved by the FAA will not be subject to related retrofit requirements that are later adopted through rulemaking. Our proposed rulemaking will include text stating that COG installations approved between the issuance of this policy statement and the adoption of a final rule that mandates a secure COG installation will be excluded from any retrofit requirement. This applies to individual airplanes and the installation design itself, so, an approved design could be used on airplanes after the effective date of a final rule. This is possible because the broad range of expertise represented on the ARC makes it unlikely that any comments received as a result of the public notice and comment process would substantively affect the retrofit designs approved on the basis of the ARC recommendations. Designs approved after the effective date of a final rule would have to comply with the retrofit requirements adopted by that final rule.
PMA holders whose articles are affected by the Airworthiness Directive and/or the SFAR may want to seek AMOC approval pursuant to the final version of this guidance. Those who expect to be seeking AMOC approval should read this draft policy very carefully to make sure it meets their needs.
Comments are due to the FAA by October 24, 2011. They can be emailed to email@example.com or mailed to:
Federal Aviation Administration
Transport Airplane Directorate
Standards Staff, ANM-115
1601 Lind Ave. SW
Renton, WA 98057-3356